(Nanowerk Information) Researchers have engineered nanosized cubes that spontaneously kind a two-dimensional checkerboard sample when dropped on the floor of water. The work, revealed in Nature Communications (“Self-assembly of nanocrystal checkerboard patterns via non-specific interactions”), presents a easy method to create complicated nanostructures by means of a way referred to as self-assembly.
“It’s a cool way to get materials to build themselves,” mentioned research co-senior creator Andrea Tao, a professor within the Aiiso Yufeng Li Household Division of Chemical and Nano Engineering on the College of California San Diego. “You don’t have to go into a nanofabrication lab and do all these complex and precise manipulations.”
Every nanocube consists of a silver crystal with a combination of hydrophobic (oily) and hydrophilic (water-loving) molecules hooked up to the floor. When a suspension of those nanocubes is launched to a water floor, they organize themselves such that they contact at their nook edges. This association creates an alternating sample of stable cubes and empty areas, leading to a checkerboard sample.
SEM picture of a checkerboard sample created by self-assembly of the nanocubes. Scale bar = 500 nm, inset = 100 nm. (Picture: Wang et al., Nature Communication)
The self-assembly course of is pushed by the floor chemistry of the nanocubes. A excessive density of hydrophobic molecules on the floor brings the cubes collectively to reduce their interplay with water. In the meantime, the lengthy chains of hydrophilic molecules trigger sufficient repulsion to create voids between the cubes, creating the checkerboard sample.
To manufacture the construction, researchers utilized drops of the nanocube suspension onto a petri dish containing water. The ensuing checkerboard will be simply transferred to a substrate by dipping the substrate into the water and slowly withdrawing it, permitting the nanostructure to coat it.
This research stems from a collaborative effort between a number of analysis teams which are a part of the UC San Diego Supplies Analysis Science and Engineering Middle (MRSEC). The work featured a synergistic mixture of computational and experimental methods.
“We’ve built a continuous feedback loop between our computations and experiments,” mentioned Tao. “We used computer simulations to help us design the materials at the nanoscale and predict how they will behave. We also used our experimental results in the lab to validate the simulations, fine tune them and build a better model.”
In designing the fabric, researchers selected silver crystal nanocubes as a result of Tao lab’s experience of their synthesis. Figuring out the optimum floor chemistry required intensive computational experimentation, which was led by Gaurav Arya, a professor within the Division of Mechanical Engineering and Supplies Science at Duke College and co-senior creator of the research. The simulations recognized the perfect molecules to connect to the nanocubes and predicted how the cubes would work together and assemble on the water floor.
The simulations had been iteratively refined utilizing experimental information obtained by Tao’s lab. Electron microscopy carried out by the lab of research co-author Alex Frañó, a professor within the Division of Physics at UC San Diego, confirmed the formation of the specified checkerboard buildings.
Tao envisions functions for the nanocube checkerboard in optical sensing. “Such a nanostructure can manipulate light in interesting ways,” she defined. “The spaces between the cubes, particularly near the corner edges where the cubes connect, can act as tiny hotspots that focus or trap light. That could be useful for making new types of optical elements like nanoscale filters or waveguides.”
The researchers plan to discover the optical properties of the checkerboard in future research.
